### Home > CC3MN > Chapter 10 > Lesson 10.2.3 > Problem10-71

10-71.

Rianna thinks that if $a=b$ and if $c=d$, then $a+c=b+d$. Is she correct?

If you add the same amount to both sides of the equals sign, then the equation remains true.

Adding $c$ to one side is the same as adding $d$ to the other because $c$ and $d$ are equal.

Therefore, the equation $(a+c=b+d)$ is correct.